import type { ChartPadding } from "./chart-types.js";
import { WebComponentBase } from "../web-component-base/web-component-base.js";
import { ChartGPURenderer } from "./gpu/chart-gpu-renderer.js";
/** Linearly maps a value from [domainMin, domainMax] to [rangeMin, rangeMax]. */
export declare const mapToRange: (value: number, domainMin: number, domainMax: number, rangeMin: number, rangeMax: number) => number;
/** Generates an array of evenly spaced tick values between min and max (inclusive). */
export declare const generateTicks: (min: number, max: number, count: number) => number[];
/** Formats a number for axis labels (compact, no trailing zeroes). */
export declare const formatAxisValue: (value: number) => string;
/** Formats a millisecond timestamp as a short date string (MM/DD). */
export declare const formatDateShort: (ms: number) => string;
declare abstract class ChartBase extends WebComponentBase {
    /** The GPU renderer shared across frames. Created on first paint. */
    protected gpuRenderer: ChartGPURenderer | null;
    /** WebGPU canvas context — configured on first paint. */
    private _gpuCanvasCtx;
    /** Externally injected GPUDevice (e.g. from brainiac-engine). */
    private _externalDevice;
    /** In-flight GPU init promise (prevents double-init). */
    private _gpuInitPromise;
    /** Whether GPU init has completed (for fast sync path). */
    private _gpuReady;
    constructor();
    /** Inject an external GPUDevice (e.g. from brainiac-engine's presentation layer). */
    set gpuDevice(device: GPUDevice | null);
    get gpuDevice(): GPUDevice | null;
    static get observedAttributes(): string[];
    attributeChangedCallback(_name: string, _oldValue: string | null, _newValue: string | null): void;
    connectedCallback(): void;
    /** Returns the chart width from the attribute or a sensible default. */
    getChartWidth(): number;
    /** Returns the chart height from the attribute or a sensible default. */
    getChartHeight(): number;
    /** Returns the padding for the plot area. Subclasses may override. */
    getPadding(): ChartPadding;
    /** Subclasses must implement the actual chart rendering here. */
    abstract paint(): void;
    /**
     * Initialise the WebGPU device, canvas context, and renderer.
     * Called automatically on first paint. Safe to call multiple times
     * (returns cached promise on subsequent calls).
     */
    protected initGPU(): Promise<void>;
    private _doInitGPU;
    /** Get the current frame's texture view for endFrame(). */
    protected getTargetView(): GPUTextureView | null;
    /** Creates or retrieves the canvas element inside the shadow root.
     *  Sets width/height attributes to match chart dimensions.
     */
    private _ensureGPUCanvas;
    /** Resolves a CSS variable from the host or returns the fallback. */
    protected cssVar(name: string, fallback: string): string;
    /** Push a background rect covering the entire canvas. */
    protected gpuDrawBackground(w: number, h: number, cssColor: string): void;
    /** Push horizontal grid lines in the plot area. */
    protected gpuDrawHorizontalGrid(padding: ChartPadding, plotHeight: number, count: number, cssColor: string, canvasWidth: number): void;
    /** Push Y-axis tick labels (right-aligned to the left padding). */
    protected gpuDrawYAxisLabels(padding: ChartPadding, ticks: number[], plotHeight: number, cssColor: string, fontSize: number): void;
    /** Parses a JSON attribute value, returning the fallback if parsing fails or the value is absent. */
    protected parseJsonAttribute<T>(name: string, fallback: T): T;
}
export { ChartBase as default, ChartBase };